Rigidbody.inertiaTensorRotation

Description

The rotation of the inertia tensor.

If you don't set intertia tensor rotation from a script it will be calculated automatically from all colliders attached to the rigidbody.

// Resets the inertia tensor to be the coordinate system of the transform
function ResetTensor() {
    GetComponent.<Rigidbody>().inertiaTensorRotation = Quaternion.identity;
}

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour {
    void ResetTensor() {
        GetComponent<Rigidbody>().inertiaTensorRotation = Quaternion.identity;
    }
}